Peptidergic innervation of the bovine vagina and uterus

The distribution of neuropeptide Y, substance P, vasoactive intestinal polypeptide, Leu5-enkephalin, bombesin/gastrin-releasing peptide, calcitonin gene-related peptide, somatostatin, cholecystokinin and catecholamine synthesizing enzymes, tyrosine hydroxylase and dopamine-beta-hydroxylase was studied immunohistochemically in nerve fibres supplying the bovine vagina and uterus. The nerves containing tyrosine hydroxylase or dopamine-beta-hydroxylase and neuropeptide Y-immunoreactivity were particularly numerous in both organs. Substance P, vasoactive intestinal polypeptide and Leu5-enkephalin-containing nerves were less numerous whereas somatostatin and calcitonin gene-related peptide-immunoreactive nerves occurred occasionally. Bombesin/gastrin-releasing peptide and cholecystokinin immunoreactivities were not present in nervous fibers of the bovine uterus and vagina. Generally, the immunoreactive nerve terminals, fibers, networks or nerve bundles were present below the serous membrane, between smooth muscle cells of muscular layers, around blood vessels, in the submucosal layer and below the luminal epithelium of the uterus and cervix.